In making integrated circuit (IC) devices, for example, it is desirable to be able to provide a plurality of conductive paths using different patterns of conductive elements which are positioned at one level and, in some cases, more than one level of a dielectric substrate. In some cases, the conductive elements are pre-arranged in the substrate to provide a plurality of pre-formed conductive paths which are then useable to provide desired conductive paths in the IC device by making appropriately selected cuts only in the already pre-formed conductive paths at selected points thereof. In some cases the conductive elements are often provided at two different levels, for example, so that in addition to such cuts vertical links must be pre-formed between conductive elements which are positioned at such two different levels.
For example, U.S. Pat. No. 4,700,214, issued on Oct. 13, 1987 to M. Johnson and U.S. Pat. No. 4,720,470, issued on Jan. 19, 1988 to M. Johnson, both disclose the use of an array of conductive pathways which are interconnected by pre-formed links. Selective conductive pathways are provided only by making appropriate cuts in the preformed conductive pathways as by using a pulsed laser to sever unaligned portions thereof as appropriate to create desired electrical circuitry.
U.S. Pat. No. 4,810,663, issued on Mar. 7, 1989 to J. I. Raffel, et al. discloses the use of conductive layers at two different levels with an insulating or dielectric layer between the two levels. Diffusion barriers are employed between the insulating layer and each of the conductive layers. Exposure of a link point to a relatively long width pulse of low power laser energy produces a vertical conductive link extending between conductive elements at each layer, the laser energy converting the dielectric material into a conductive path at the vertical link site.
U.S. Pat. No. 5,087,589 issued on Feb. 11, 1992 to Chapman et al. discloses the use of an ion implantation technique for producing conductive links between conductive elements.
IBM Technical Disclosure Bulletin, Vol. 17, No. 1 of Jun. 1994 by P. W. Cook et al. discloses the use of aluminum metallization highways which are joined to underlying interconnection tracks which are diffused into the surface of a substrate.
U.S. Pat. No. 4,937,475, issued on Jun. 26, 1990 to Rhodes, and U.S. Pat. No. 4,240,094, issued on Dec. 16, 1980 to Mader, disclose the provision of links between conductive elements at two different levels, which link is provided at still a third level using a diffusion technique to link the conductive elements at the two other levels.
U.S. Pat. No. 4,701,860, issued on Oct. 20, 1987 to Mader discloses programmable architecture for laying out circuitry but does not disclose specific techniques for forming links between metal elements.
While the above approaches discuss the formation of conductive paths so as to provide useable IC circuits, the density of the paths and the reliability thereof is not as high as may be desired in many applications. There is a need, for example, to make such IC devices as small as possible by providing as high a density of conductive paths for forming circuitry therein as can be achieved. Moreover, it is desirable to do so while providing high yields for such devices, i.e., the formation of the desired configurations of conductive paths must be highly reliable so that fewer devices are subject to rejection in the production thereof.